NYPD police Community Affairs walk by police tape outside the entrance of an apartment building where a New York City police sergeant fatally shot a 66-year-old woman who charged him with a baseball bat at her apartment on Tuesday in the Bronx borough of

NEW YORK (Reuters) - The death of a 66-year-old emotionally disturbed black woman who was shot after allegedly swinging a baseball bat at a police sergeant inside her New York apartment "didn't have to happen," the city's mayor said on Wednesday.

"It's quite clear that our officers are supposed to use deadly force only when faced with a dire situation," Mayor Bill de Blasio told reporters. "It's hard for any of us to see if that standard was met here."

The fatal shooting of Deborah Danner followed a number of incidents that have put law enforcement across the United States under intense scrutiny over the use of excessive force, especially against minorities and the mentally ill.

Officers received an emergency call at about 6 p.m. on Tuesday from a neighbor who said Danner was acting irrationally, police said. When police Sergeant Hugh Barry entered her apartment in the city's Bronx borough he found Danner clutching scissors in a bedroom, police said.

Barry convinced Danner to put down the scissors, but she then picked up a baseball bat and charged at him, police said. Danner tried to strike the sergeant and he fired two shots from his service revolver, striking her in the torso, police said.

The mayor told a news conference that he had spoken with Danner's sister and caretaker, Jennifer Danner, and that she told him police had been called to the apartment before without any problems.

"She was standing there in that hallway, ready to go the hospital," de Blasio said, referring to the sister. "She told me she did not in any way expect to hear gunshots ring out."

De Blasio said Barry, who is white and an eight-year veteran of the New York City Police Department, received some training under a new department program that includes de-escalation techniques.

The mayor said Barry has been placed on modified duty.

The police department is investigating and will examine why the sergeant did not use a Taser instead of opening fire.

A representative for the police union could not be reached for comment. It could not be determined immediately if Barry has retained legal counsel.

Police Commissioner James O'Neill called the incident "distressing" and said the NYPD's procedures for handling emotionally disturbed people had not been followed.

The New York City Police Department has 34,500 uniformed officers. O'Neill, who became the department's head after William Bratton retired in September, designed its neighborhood policing program to improve relations between police officers and the communities they patrol.

The Bronx Borough president, Ruben Diaz Jr, a former state lawmaker, called the shooting an "outrage."

"This elderly woman was known to the police department, yet the officer involved in this shooting failed to use discretion to either talk her down from her episode or, barring that, to use his stun gun," Diaz said in a statement. "That is totally unacceptable."

(Reporting by Gina Cherelus in New York; Additional reporting by Alex Dobuzinskis in Los Angeles; Editing by Christian Schmollinger and Leslie Adler)